Husbands smelly feet/athletes foot.?

My husband has extremely smelly feet has since he was a little kid. When I wash his socks they are almost completely stiff. He says he has had athletes foot his whole life. How does someone have something like that for their whole lives? How can we rid this completely and how can we cure his smelly feet? He freaks out any time I go near his feet or whenever I accident bump his feet bc he doesn't want me to get it... lol?? I just need to better understand this and find a cure. A REAL CURE.